The present invention relates to an article and a method for making the article, the article being a lifter element for use in a disc cartridge. Particularly, the invention provides a cost effective means of configuring and producing the lifter element.
Typically for hard-type magnetic disc cartridges, a hard case made of synthetic resin material contains a magnetic disc rotatably therein. The magnetic recording medium of the magnetic disc is thus protected from exposure to the outside, but through which an opening is provided to read information from the disc. In FIGS. 1-4, there is shown a conventional hard-type magnetic disc cartridge comprising a case which is composed of a cover member 1 and a bottom member 2, and a magnetic disc 3 which is rotatably contained in the hard case. The cover member 1 and the bottom member 2 are typically made of a synthetic resin material by molding.
On the inner surfaces of the cover member 1 and the bottom member 2, liners 4, 5 are attached on the opposite sides of both surfaces of the magnetic disc 3. The liners are made of a soft material. The case, composed of the cover member 1 and the bottom member 2, contains a space 6 having a height H.sub.1 which is larger than a thickness t.sub.1 of the magnetic disc 3.
The bottom member 2 is provided with a circular opening 21 in its center position along a pivot center 0, and an anti-abrasion chip 7 having a circular form is attached to the inner center of the cover member 1.
As shown in FIGS. 3 and 4, the cover member 1 and the bottom member 2 are further provided with windows 8, 9, respectively, one for each member, in their corresponding position through which the magnetic head may be inserted. The windows 8 and 9 are closed by shutters 10 when they are not used as shown in FIG. 1.
The magnetic disc 3 comprises a stepped hub portion 31 in its center, which is made of a metal or a synthetic resin material, and an annular ring, magnetic recording medium 32 which is coaxially connected to the periphery of the hub portion 31. The hub portion 31 is provided with an opening 33 in its center, through which the pivot shaft of the magnetic disc drive means is inserted. When the magnetic disc 3 is contained in the case, a circular ring projection 39 of the cover member 1 is positioned inside of the inner diameter part of the hub portion 31 of the magnetic disc 3 and the outer surface of the hub portion 31 is exposed to the central circular opening 21 of the bottom member 2 so that the magnetic recording medium 32 of the magnetic disc 3 may be completely covered by the cover member 1 and the bottom member 2 therebetween.
As shown in FIGS. 3 and 4, the upper case part 1 provides raised ribs 40 facing the lower cartridge part 2. The ribs 40 are arranged on the case side of the liner 4. On the lower part 2 is arranged a lifter 44 which is generally a thin piece of synthetic material anchored with adhesive 46 along one end thereof to the case 2 and wherein a rib 48 is applied to the case to flex a cantilevered portion 50 of the lifter 44 toward the liner 5. As shown in FIG. 2, when the upper cover 1 is connected to the lower part 2, the ribs 40 are opposed to the lifter 44 and the cantilever part 50 resiliently clamps the disc 32 between the liners 4, 5. This creates a wiping action as the disc 32 rotates through the region of the lifter 44 and the ribs 40 against the liners 4, 5. It is noted in FIGS. 3 and 4 that the liners 4, 5 are secured by adhesive or heat sealing 52 around their edges except the liner 4 is not heat sealed to the cover 1 in a region 54 to allow the liner for some flexibility to move under influence of the ribs 40 and the liner 5 is not adhesively secured to the lower part 2 in a region 56 to allow flexibility of movement under influence of the lifter 44.
It is known in the manufacture of lifters 44 to use an adhesive 46 in a lower region 58 of each lifter and to temporarily arrange a plurality of lifters 44 along a film strip 60 having tractor holes 62 applied thereon as shown in FIG. 5. The film strip 60 can be shipped in strips from the factory to the assembler of the cartridges.